Compounds having a musk odor play a prominent role in the perfume industry. Because of their unique property of harmonizing perfume compositions, imparting character thereto and at the same time increasing tenacity, musk fragrances are nowadays to be found in significant amounts in almost every perfume oil. Accordingly, the worldwide annual requirement for musk fragrances is several thousand tons. By far the largest part is provided by "polycyclic aromatic" musk compounds. Typical examples of this class of compound are HHCB (commercial product, e.g. GALAXOLIDE.RTM.) and AHTN (commercial product, e.g. TONALIDE.RTM.) ##STR1##
They are prepared in considerable amounts on an industrial scale and are thus available at a very favorable cost.
It has recently been discovered that polycyclic aromatic musk fragrances are not readily biodegradable and consequently, as extremely lipophilic compounds, exhibit bioaccumulative behaviour, i.e. they are able to accumulate in the fatty tissue of organisms.
In the perfume industry, there is thus an urgent need for biodegradable musk fragrances which are suitable both in terms of their odiferous properties as well as in terms of price level to replace the polycyclic aromatic compounds.
In contrast to the polycyclic aromatic compounds, macrocyclic musk fragrances are biodegradable. The market prices for these compounds, however, are several times those of polycyclic aromatic compounds. The general formula for macrocyclic musk fragrances is: ##STR2##
One relatively good value compound within the group of macrocyclic musk fragrances is the cyclic ethylene glycol ester of dodecanedicarboxylic acid (ethylene dodecanedioate, available commercially, for example as AROVA N from Huls). Because of its odiferous properties, however, this compound is not a suitable replacement for polycyclic aromatic musk fragrances. Surprisingly, we have, however, found that the addition of the lower homologue, the cyclic ethylene glycol ester of undecanedicarboxylic acid (ethylene undecanedioate), brings about an odiferous effect which is notable because the resulting mixture is considerably more like the odor type of the polycyclic and aromatic musk fragrances. Although the odiferous properties of ethylene undecanedioate have previously been described as "weakly musk-like, sweet" (S. Arctander; Perfume and Flavour Chemicals, published privately, Montclair N.J., 1969, Monograph 1228), there is no indication in the literature of an odiferous relation to polycyclic aromatic musk fragrances, making the observed effect in combination with ethylene dodecanedioate not foreseeable, but completely surprising.